Apparatus for continuously embedding flexible cable in plaster ceilings



26 36 m\ Km 2 Sheets-Sheet 1 LIVERMO'RE Thomas L Livermore JNVENTOR APPARATUS FOR CONTIN-UQUSLY EMBEDDING FLEXIBLE CABLE IN PLASTER CEILINGS Nov.21, 1967 Filed May 2, 1966 T. L.- LIVERMORE APPARATUS FOR CONTINUOUSLY EMBEDDING Nov. 21, 1967 3,353,323

FLEXIBLE CABLE IN PLASTER CEILINGS v 2 Sheets-Sheet 2 Filed May 2, 1966 R m .O mw m w L L S W Y OB 1H T Ill \1 United States Patent 3,353,323 APPARATUS FOR CONTINUOUSLY EMBEDDHJG FLEXIBLE CABLE IN PLASTER CEILINGS Thomas L. Liver-more, 1543 N. Fir, Tacoma, Wash. 98406 Filed May 2, 1966, Ser. No. 546,848 11 Claims. (Cl. 52-749) This invention relates to apparatus for continuously embedding electric heating or other flexible cable in plaster or sheet rock covered ceilings.

The advantages of applying radiant heating techniques to space heating are well known. However, a principal deterrent to the wide spread use of such techniques is the high cost of embedding the electric heating cable in the ceiling.

For example, in one conventional method of applying such cable, the ceiling is covered with a first layer of sheet rock, lath is applied, the cable is tacked manually to the sheet rock, and a brown coat coat of plaster is applied over the lath and over the cable, embedding the latter. Thereafter, a finish coat of plaster or sheet rock is applied.

The principal object of the present invention is to provide apparatus for embedding electric heating cable and like flexible elements in plaster or sheet rock ceilings on a rapid continuous basis which makes possible application rates of as much as 3000 feet of cable per hour.

It is another object of the present invention to provide apparatus for embedding electric heating cable in plaster and plasterboard ceilings which results in accurate and safe application of the cable.

Still another object of the invention is the provision of electric heating cable applying apparatus which is of simple, inexpensive construction and easy to use.

The manner in which the foregoing and other objects of this invention are accomplished will be apparent from the accompanying specification and claims considered together with the drawings, wherein:

FIG. 1 is a view in side elevation of the presently described apparatus for embedding electric heating cable in plaster ceilings;

FIG. 2 is a detail transverse sectional view, taken along line 2-2 of FIG. 1 and illustrating particularly the resilient mounting of the working elements of the apparatus;

FIG. 3 is an enlarged fragmentary view in side elevation, similar to FIG. 1, but showing the top part of the apparatus only, for illustrating the manner of functioning of the working elements of the apparatus;

FIG. 4 is a transverse sectional view, taken along line 44 of FIG. 3, and showing the arrangement of the working elements of the apparatus in their operating se quence; and

FIG. 5 is a fragmentary view in elevation looking .in the direction of the arrows of line 55 of FIGIB and illustrating the manner of resiliently mounting the operating elements of the apparatus to bring them into operative contact with the ceiling.

Basically considered, the presently described apparatus for embedding electric heating cable and like flexible elements in plastered or sheet rock covered ceilings comprises a mobile frame extending vertically substantially from the fioor to the ceiling and adapted to move along a predetermined path. Cutter means are mounted on top of the frame for continuously cutting a trench of predetermined dimensions in the ceiling as the frame moves along its selected path.

Cable laying means are mounted on the frame behind the cutter means for laying flexible cable continuously in the trench excavated by the cutter. Suitable plastic filler applying means are mounted on the frame behind the cable laying means for filling the trench continuously with un- "ice cured, settable plastic material, thereby embedding the cable in the ceiling.

In addition, a smoothing element may be included for smoothing over the surface of the freshly laid plastic material. Still further, there may be included in the assembly air jet means for blasting debris from the cut trench, and vacuum air filter means located adjacent the cutter for removing from the atmosphere dust created during operating of the cutter.

Considering the foregoing in greater detail and with particular reference to the drawings:

The cable laying apparatus of my invention is mounted on a mobile frame which includes a base made up of a pair of vertically spaced, horizontal, platform plates 10, 12. A pair of support wheels 14 is journaled on an axle 16 supported on the underside of plate 12 in the usual manner. A centrally mounted steering wheel 18 is pivoted to the underside of plate 12, forwardly thereof. A central, swiveling, stabilizing wheel 20 also is mounted on the underside of plate 12, rearwardly thereof.

The platform comprising plates 10 and 12 supports a telescoping tower designed to bring the working elements of the apparatus in close proximity to the ceiling, and maintain them there during the cable embedding operation.

To this end there are provided a pair of vertical standards 22 mounted in spaced relation on platform member 10 and tied together by guide plates 24, 26. Standards 22 receive between them in sliding engagement a pair of extension segments 28, maintained in spaced, parallel relation by means of spacing blocks 30, 32.

Resilient means are provided for resiliently interconnecting standards 22 and vertically sliding extensions 28.

In the illustrated form of the invention the resilient means comprises a long coil spring 34, the lower end of which is bolted to spacing block 30 between the lower ends of extensions 28, and the upper end of which is hooked over a pin 36 which spans plates 26 bolted across the upper ends of standards 22, FIG. 2.

Supported on the upper ends of extensions 28 is a frame sub-assembly which mounts the operating units of the apparatus and maintains them pressed snugly against the ceiling.

The construction of the subframe is shown particularly in FIG. 3. It includes a lower horizontal plate 40 fixed to standard extensions 22, and an intermediate plate 42 spaced vertically from plate 40 by means of post pairs 44, 46, 48. Posts 48 are hinged to plate 40 by means of hinges 49.

Intermediate plate 42 has attached to it a coplanar extension 50, the inner end of which is attached to posts 46 by hinges 52, and the outer end of which is provided with locating notches 54 which seat over the upper ends of supporting posts 48.

A third and uppermost frame sub assembly plate 56 also is formed in two sections. Plate 56 overlies and is substantially codimensional with intermediate plate 42. An independent coplanar extension 58 overlies and is substantially coextensive with hinged section 50 of the intermediate plate.

Plate 56 and extension 58 both are relatively movable in a vertical direction with respect to intermediate plate sections 42, 50. They are maintained pressed resiliently upwardly by means of resilient mounting posts indicated generally at 60.

Each post 60 comprises telescoping upper and lower sections 62, 64 respectively, the outer ends of which are threaded into drilled and tapped recesses in upper plates 56, 58. A compression spring 66 is seated within overlapping telescoping section 62, bearing against the inner end of underlapped section 64 to provide the desired resilient action.

The frame assembly thus provided may be piloted along a predetermined course by a steering assembly which is shown in FIG. 1.

A vertical steering post 70 is journaled in bearings mounted in an intermediate platform unit 72 supported on standards 22 and also in a bearing mounted in lower plate 10. The upper end of the post is provided with a transverse steering handle 74 as well as with a steering indicator 76 so fixed to post 70 that when the indicator is parallel with the longitudinal center line of the mobile frame, the frame will move in -a straight line, directly ahead. If desired, the upper surface of plate 72 which underlies pointer 76 may be calibrated to indicate angular direction of the frame.

Steering post 70 is connected to steering wheel 18 through connecting linkages including pulley '78 keyed to the lower end of post 70, pulley 8t) keyed to the shaft 82 of steering wheel 18, and a connecting belt 84. Accordingly an operator pus-hing the apparatus from behind can steer it precisely by manipulating handle 74, noting the angle of indication of pointer 76.

The operating elements of the apparatus and their operational relationship are particularly evident in FIG. 3.

First, cutting means are provided for cutting a trench of predetermined depth and width in a plaster or sheet rock ceiling 90. Several forms of cutting tools may be employed.

The form illustrated in the drawings is a conventional router 92 coupled to a rotary electric motor 94 mounted adjustably on the moving, telescoping segment of one of posts 60. It will be apparent that the degree of projection of the router head beyond the plane of the upper surface of plate 56 will determine the depth of the trench; the diameter of the router head, its width.

As an alternate form of cutter means there may be employed parallel rotary saws of conventional construction, also driven by a rotary, electric motor. In this application, the projection of the saws beyond plate 56 will determine the depth of the cut, while the spacing between the saws will determine its width.

Second, there is provided, optionally but preferably, air jet means for cleaning the trench excavated by cutter 92.

As illustrated, the air jet means may comprise an air compressor 96 driven by motor 98 and feeding a compressed air line .100. The air line includes a control valve 102 and terminates in a nozzle 104. The nozzle is mounted in plate 56 directly behind cutter 92.

Third, again optionally but preferably, air filter means are provided for removing from the atmosphere the dust generated by the cutting and jetting operations. To this end there is provided a vacuum filter 110, which may be of the electric motor driven vacuum cleaner type. A fieXi ble conduit 112 is connected to the filter. The conduit passes through and is guided by intermediate frame plate 72 and upper frame plates 40, 42. It terminates in a receiving tube 114 located just beneath the cutting and jetting units of the assembly.

Fourth, cable applicator means are provided for placing in the cleaned trench the electric heating cable or other flexible element indicated at 120.

The cable laying assembly includes a horizontal post 122 extending outwardly from standard 22. Post 122 rotatably supports a reel 124 on which cable is wound. The running end of the cable runs through a guideway in hinged support plate extension 50 and then through a cutaway guide opening 126 in the inner margin of top plate segment 58.

Fifth, means are provided for filling the trench containing the entrenched cable with plaster or other plastic, settable material.

The plaster applying assembly includes a pressure storage vessel 130 containing a plastic filler of the desired consistency. Air under pressure is applied to the vessel through spur line 132 coupled to air line 100, leading from compressor 96.

An exhaust line 134 discharges plastic material from: storage vessel 130. The flow of plastic material through: line 134 is controlled by means of valve 136, which may be solenoid operated if desired.

Line 134 terminates in a nozzle 136 pressed in a guide opening 138 through segment 58 of the upper support plates. The nozzle thus is located directly behind cable laying guideway 120.

Sixth, means are provided for smoothing the uncured plastic material discharged into the trench by nozzle 136. Such means comprise the smooth upper surface of plate 58 which may be contoured as desired to serve as a leveling or smoothing shoe which presses the plastic material into the trench, thoroughly embedding cable 120, and smooths over the exposed surface.

OPERATION The operation of the herein described apparatus is as follows:

Reservoir 130 is charged with uncured plaster and the motors driving compressor 96, vacuum air filter and router )2 set in operation.

S ring 34 is adjusted to press the upper portion of the assembly snugly against the ceiling.

The line of application is marked out on the ceiling.

The line then is followed -by the operator, manually pushing or pulling the apparatus, and steering it by means of handle 74 which operates steering wheel 18. The direction of movement is determined by noting the position of pointer 76 with reference to the underlying surface of plate 72.

As the apparatus progresses, router 92 digs a trench in the solid ceiling. Air .jet 104 blasts away the debris. Nozzle 114 of vacuum air filter 110 collects the finely divided dust.

Cable pays out automatically from reel 124 and is pressed by the guiding leading surface of plate 58 into the trench. Nozzle 136 fills the trench with uncured plaster or other settable plastic filler. Shoe 58 presses the freshly applied plaster into the trench. It also smooths over the exposed surface of the plaster and leaves the ceiling ready for painting when the plaster has set.

There thus is provided an apparatus which in a single pass accomplishes all of the operations necessary for laying cable in a plaster or sheet rock ceiling. The cable may be laid with great accuracy and minimum inconvenience. In addition, it can be laid at a high rate of speed, i.e. a speed of from 1000-3000 feet of cable per hour, thus making possible the economical and practical application of radiant electric heating cable in ceiling applications.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. Apparatus for embedding electric heating cable and like flexible elements in plaster ceilings which comprises (a) a mobile frame extending vertically substantially from the fioor to the ceiling and adapted to move along a predetermined path,

'(b) cutter means mounted on top of the frame for cutting continuously a trench of predetermined dimensions in the ceiling as the frame moves along said path,

(c) cable laying means mounted on the frame behind the cutter means for laying continuously a flexible cable in the trench, and

(d) plastic filler applying means mounted on the frame behind the cable laying means for filling continuously the trench with uncured plastic filler, thereby embedding the cable in the ceiling.

2. The apparatus of claim 1 including shoe means resiliently mounted on the frame behind the filler applying means and arranged for continuously smoothing the surface of the filler.

3. The apparatus of claim 1 including air jet means mounted on the frame between the cutter means and cable laying means and arranged for directing a jet of compressed air into the trench for cleaning the same.

4. The apparatus of claim 1 including vacuum air filter means mounted on the frame and including a vacuum duct disposed adjacent the cutter means for receiving the dust and debris resulting from the operation of the same.

5. The apparatus of claim 1 wherein the mobile frame includes a platform base mounted on wheels, one of the wheels being a pivotally mounted forward steering wheel, and including also pivotally mounted vertical steering post means positioned adjacent the operator and coupled to the steering wheel.

6. The apparatus of claim 1 wherein the mobile frame includes a vertically arranged telescoping tower containing upper and lower sections, and resilient means interconnecting the upper and lower sections for urging the upper section resiliently in the direction of the ceiling.

7. The apparatus of claim 1 wherein the mobile frame includes a vertical tower mounting on its top a pair of vertically spaced, relatively movable platforms, the upper platform mounting the cutter means, the cable laying means and the plastic filler applying means, and a plurality of vertically arranged horizontally spaced resilient cylinders interconnecting the upper and lower platforms for urging the upper platform continuously in the direction of the ceiling.

8. The apparatus of claim 1 wherein the cutter means comprises a rotary router and drive means therefor.

9. The apparatus of claim 1 wherein the cutter means comprises a pair of horizontally spaced rotary saws and drive means therefor.

10. The apparatus of claim 1 wherein the cable laying means comprises a post disposed on the frame for rotatably mounting a reel of the cable, guide means for guiding the running end of the cable to the vicinity of the trench, and second guide means on the frame immediately adjacent the ceiling for guiding the cable into the trench in the longitudinal direction thereof.

11. The apparatus of claim 1 wherein the plastic filler applying means comprises a pressure reservoir communieating with a source of air under pressure, a conduit communicating with the reservoir and terminating in a nozzle, means for mounting the nozzle to direct the flow of plastic filler material into the trench, and valve means included in the conduit for conforming the rate of flow of the plastic filler material to the rate of travel of the mobile frame.

References Cited UNITED STATES PATENTS 725,340 4/1903 Hightower 61----72.6 2,187,223 1/1940 Cory 52749 3,203,188 8/1965 Evans 61--72.6

FRANCIS K. ZUGEL, Primary Examiner. 

1. APPARATUS FOR EMBEDDING ELECTRIC HEATING CABLE AND LIKE FLEXIBLE ELEMENTS IN PLASTER CEILINGS WHICH COMPRISES (A) A MOBILE FRAME EXTENDING VERTIALLY SUBSTANTIALLY FROM THE FLOOR TO THE CEILING AND ADAPTED TO MOVE ALONG A PREDETERMINED PATH, (B) CUTTER MEANS MOUNTED ON TOP OF THE FRAME FOR CUTTING CONTINUOUSLY A TRENCH OF PREDETERMINED DIMENSIONS IN THE CEILING AS THE FRAME MOVES ALONG SAID PATH, (C) CABLE LAYING MEANS MOUNTED ON THE FRAME BEHIND THE CUTTER MEANS FOR LAYING CONTINUOUSLY A FLEXIBLE CABLE IN THE TRENC, AND (D) PLASTIC FILLER APPLYING MEANS MOUNTED ON THE FRAME BEHIND THE CABLE LAYING MEANS FOR FILLING CONTINUOUSLY THE TRENCH WITH UNCURED PLASTIC FILLER, THEREBY EMBEDDING THE CABLE IN THE CEILING. 